We are investigating a number of problems with the eucaryotic organism Saccharomyces cerevisiae (yeast) that deal with (1) mechanisms of genetic recombination, (2) the mating-type locus as an example of a complex locus of regulatory importance to the cell, (3) the regulation of translation as revealed by studies of suppressors and their modifiers, (4) the characterization of chromosomal DNA with reference to the correspondence of specific molecules to specific linkage groups, and (5) the role of proteases in regulating cell functions.